By Randy Parks
Burns Times-Herald

Butterflies or moths? Harmless or a threat to the forest? Those are questions people have been asking after encountering a large number of the winged insects north of Burns.

While some have wondered if they are tree-eating moths, the truth is they are Pine White butterflies. If you drive north on Highway 395, you’ll more than likely see hundreds, if not thousands of the flitting creatures.

According to the Web site www.butterfliesandmoths.org, the butterfly’s scientific name is Neophasia menapia and other facts are as follows:

Identification: The upperside of forewing has a mostly all white cell and black band along costal margin, and the underside of hindwing has black veins. The female of the species resembles the male, but is duller; hindwings often have red edges, tinged with yellow

Life history: Males patrol near host trees for females. Eggs are laid stuck together in a row on a conifer needle. Caterpillars feed in groups when they are young and move apart when they are older. Caterpillars pupate at the base of the host tree after descending from the tree on a silken thread. Eggs hibernate.

Flight: One flight June-September.

Wing span: 1 3/4 - 2 1/4 inches (4.5 - 5.8 cm).

Caterpillar hosts: Needles of various conifers including pines (Pinus species), Douglas-fir (Pseudotsuga menziesii) and true firs (Abies species).

Adult food: Flower nectar including rabbitbrush, other yellow-flowered composites, and monarda.

Habitat: Western coniferous forests.

Range: British Columbia east to Alberta, south through Rocky Mountain states and California to Mexico; range just extends into western South Dakota and western Nebraska.

Conservation: Not usually needed.

NatureServe Global Status: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management needs: Caterpillar outbreaks occasionally defoliate ponderosa pine stands (Pinus ponderosa).